Painting worth £1m with Nelson Mandela link found being used as kitchen pinboard

'Arab in Black' by Irma Stern was once sold to help fund Nelson Mandela's legal defence Bonham's

It’s not every day that your kitchen pinboard turns out to be an artwork worth up to £1 million, but that’s exactly what happened to one London flat owner.

Bonhams art expert Hannah O’Leary was on a valuation visit when she spotted late South African artist Irma Stern’s painting “Arab in Black” hanging on the wall, “covered in letters, postcards and bills” and set in an antique timber frame.

The 1939 masterpiece, of an Arab man in a colourful turban, was once sold to help pay Nelson Mandela’s lawyers so holds huge political significance.

Giles Peppiatt, director of Bonhams South African art department, told the Guardian that the painting was a key part of Mandela’s defence fund when he was handed a life sentence for treason.

“The words ‘shocked’ and ‘astonished’ would both apply to the present owners,” he said. “They loved the painting and they knew it had some value but they had no idea it was such an important work.

"In some ways they are very sorry to see it go, but it would be a great luxury to keep a million-pound painting hanging on a kitchen wall.”

The present owner’s parents brought the painting to the UK when they emigrated in the Seventies. It will be resold at Bonhams South African Art auction in London on 9 September.

Stern’s art has been rising in popularity and value recently, with another painting framed similarly to “Arab in Black” selling for a world record price of £3.1 million at Bonhams four years ago.